On Friday, October 16, 2015 at 9:24:20 AM UTC-4, wrote:
I am trenching 4 inch pipe from my down spots away from my house. I am debating on whether the pipe should end above ground or use one of those pop up elbows.

Does one way seem better than another? My worry with just exiting on top of the ground is possible freezing in winter. I live in KY, so it is not like Canada or anything but it does freeze.

Thanks!

My advice (from a New Yorker) is to not risk a freeze with the popups. You eventually will end up with a freeze and a solid downspout. If you have sufficient pitch away from the house, trench and bury between the house and the outlet (so you can have a lawn over the pipe), and end by daylighting the pipe and putting a few large stones around it (so you don't hit the outlet with the lawnmower). The added benefit is that any stray leaves won't clog this solution, but may clog a popup.